Pseudoaneurysm of the left ventricle progressing from a subepicardial aneurysm.

A 56-year-old man presented with an inferior myocardial infarction and a huge pseudoaneurysm below the inferior surface of the left ventricle, which had progressed from a small subepicardial aneurysm over a 6-month period. Transthoracic echocardiography, Doppler color flow images, radionuclide angiocardiography, magnetic resonance imaging and contrast ventriculography all revealed an abrupt disruption of the myocardium at the neck of the pseudoaneurysm, where the diameter of the orifice was smaller than the aneurysm itself, and abnormal blood flows from the left ventricle to the cavity through the orifice with an expansion of the cavity in systole and from the cavity to the left ventricle with the deflation of the cavity in diastole. Coronary angiography revealed 99% stenosis at the atrioventricular nodal branch of the right coronary artery. At surgery the pericardium was adherent to the aneurysmal wall and a 1.5-cm orifice between the aneurysm and the left ventricle was seen. Pathological examination revealed no myocardial elements in the aneurysmal wall. The orifice was closed and the postoperative course was uneventful. Over-intense physical activity as a construction worker was considered to be the cause of the large pseudoaneurysm developing from the subepicardial aneurysm. These findings indicate that a subepicardial aneurysm may progress to a larger pseudoaneurysm, which has a propensity to rupture, however, it can be surgically repaired.